The HTC One X ships with Android ICS (Ice Cream Sandwich) v4.0.3, with HTC’s Sense 4.0 overlay. Overall, we really like the additions offered by Sense 4.0 and the build of ICS on the phone just feels more polished than some others we have experienced.
Out of the box, the home screens aren’t overly cluttered, but they can be quickly and easily customized anyway. Responsiveness to touch is excellent on the HTC One X, perhaps the best we have experienced on any device. There is virtually no lag when touching / dragging items, pinch to zoom is fluid and responsive, and transition animations are smooth as silk. Launching applications is also very quick—the device just feels fast.
The true HD Super-LCD screen on the HTC One X is also very good. Colors are vibrant without seeming overly saturated and the screen has excellent brightness. The glossy display is somewhat hard to see in direct sunlight, but that is par for the course with smartphones today. Viewing angles are very good, which makes for easy sharing of content with others around you, even when not directly in front of the device. The true HD Super-LCD screen itself offers a relatively high resolution of 1280x720, which results in crisp and sharp images that rival the best smartphones available today.
In addition to the standard fare included with Android 4.0, the HTC One X comes preloaded with a number of other applications. Preloaded on the device are HTC Watch, Facebook, Twitter, YouTube HD, Google Maps, Google Talk, and Amazon Kindle, along with a few AT&T branded apps, namely AT&T Navigator, Hotspots, Family Map, U-Verse Live TV, Code Scanner, My Wireless, Ready2Go, and YP Mobile.
Using the actual phone portion of the HTC One X was also very good (you know, these things can actually make calls). Sound quality making calls is excellent--we sounded well on the recipient's end and callers sounded good to us. The One X held onto calls as good or better than other phones we've tested as well.